19.2.3.2 LIST COLUMNS partitioning

MySQL 5.5 provides support for LIST
COLUMNS partitioning. This is a variant of
LIST partitioning that enables the use of
multiple columns as partition keys, and for columns of data
types other than integer types to be used as partitioning
columns; you can use string types,
DATE, and
DATETIME columns. (For more
information about permitted data types for
COLUMNS partitioning columns, see
Section 19.2.3, “COLUMNS Partitioning”.)

Suppose that you have a business that has customers in 12
cities which, for sales and marketing purposes, you organize
into 4 regions of 3 cities each as shown in the following
table:

Region

Cities

1

Oskarshamn, Högsby, Mönsterås

2

Vimmerby, Hultsfred, Västervik

3

Nässjö, Eksjö, Vetlanda

4

Uppvidinge, Alvesta, Växjo

With LIST COLUMNS partitioning, you can
create a table for customer data that assigns a row to any of
4 partitions corresponding to these regions based on the name
of the city where a customer resides, as shown here:

As with partitioning by RANGE COLUMNS, you
do not need to use expressions in the
COLUMNS() clause to convert column values
into integers. (In fact, the use of expressions other than
column names is not permitted with
COLUMNS().)

It is also possible to use DATE
and DATETIME columns, as shown
in the following example that uses the same name and columns
as the customers_1 table shown previously,
but employs LIST COLUMNS partitioning based
on the renewal column to store rows in one
of 4 partitions depending on the week in February 2010 the
customer's account is scheduled to renew:

This works, but becomes cumbersome to define and maintain if
the number of dates involved grows very large; in such cases,
it is usually more practical to employ
RANGE or RANGE COLUMNS
partitioning instead. In this case, since the column we wish
to use as the partitioning key is a
DATE column, we use
RANGE COLUMNS partitioning, as shown here: